Fig. 3

Normalized phased array beampatterns with \(\theta _d = 0^{\circ }\). a Beampattern when \(M=5\), \(M=10\), and \(M=15\), and \(d = \frac{\lambda }{2}\). b Beampattern for a 10-elements phased array when \(d = \lambda\), \(d = \frac{\lambda }{2}\), and \(d = \frac{\lambda }{4}\)